Musculoskeletal conditions are exceptionally common and costly to treat. In a 2002 survey of US adults 26 percent reported back pain and 14 percent reported neck pain in the previous three months. Expenditures to treat spine conditions alone accounted for at least 9 percent of 2005 US health care expenditures. Although all health care providers treat these conditions, patients with musculoskeletal problems make up the majority of visits to Complementary and Alternative Medicine (CAM) providers (chiropractors, acupuncturists, massage therapists, and naturopathic physicians) and randomized controlled trials have shown some CAM therapies for back pain are equally if not more efficacious than conventional care. This study will use secondary data from the Medical Expenditure Panel Survey and 5 years of Washington State Insurance Claims (from approximately 1.5 million people) to evaluate whether patients who use CAM providers for the treatments of musculoskeletal conditions are managed with less cost and utilization of conventional medical services when compared to patients who do not use CAM providers. Selected indicators of care quality will also be assessed for patients who have low back pain. Because self-selection of patients into various treatment groups confounds observational data, this study will compare several risk adjustment tools assessing patients'baseline utilization profile and adjusting for other factors that confound utilization analyses. Together, these analyses will inform policy makers, providers, and patients about whether CAM is an efficient alternative to usual and customary care. These studies will also aid clinicians and policy makers in selecting the appropriate diagnostic and therapeutic techniques for patients with musculoskeletal conditions. PUBLIC HEALTH RELEVANCE: This study will evaluate cost, service utilization, and quality of care for patients with musculoskeletal conditions. CAM users and CAM non-users will be compared.